1. Field of the Invention
This invention relates to apparatus for controlling a plurality of output shafts and more particularly to an electronic motion generator for positioning a plurality of slave shafts in response to a master axis motion input.
2. Description of the Prior Art
In drive control, a profile is the description of the operation or movement of a motion drive, usually expressed as a time versus location curve for one full cycle of the drive. That is, the control profile is a description of how the output position of a slave follows the master input position. The slaves are usually driven mechanically by gears, cams, levers, chains, belts, or the like. The main drive shafts are driven through many cycles, and the slave shafts follow their profile position through each cycle to accomplish multi-step operations such as assembling, testing, or packing various items. The speed of the main drive shaft can vary and the speed and positioning of the associated slave shafts must also vary accordingly.
Conventional prior art mechanical drive controls provide power takeoff for each motion drive from a main mechanical line shaft. A heavy machine support base is required to maintain alignment of the line shaft and power takeoffs. Many mechanical components with inherent friction and inertia are required, resulting in drive power waste. Machine timing is difficult to set or change and the high mechanical wear rate tends to alter timing. It is difficult to alter motion amplitude, velocity, or acceleration, and such changes require installation of change parts such as new gears, sprockets, cams or the like. Mechanical over load clutches are required for torque control.